The dose-dependent effect of remifentanil for withdrawal responses on injection of recuronium in children

ABSTRACT

BACKGROUND: The injection of rocuronium causes pain and withdrawal responses. This study was designed to determine an appropriate dose of remifentanil to prevent the withdrawal responses associated with injection of rocuronium in children. METHODS: Fourty five ASA physical status I and II pediatric patients were randomly allocated into three groups; Group I (placebo; normal saline 3 ml, n = 15), Group II (remifentanil 0.3microg/kg, n = 15), Group III (remifentanil 0.5microg/kg, n = 15). After the induction of anesthesia with 5 mg/kg of thiopental sodium, patients in groups I, II, and III received normal saline 3 ml, remifentanil 0.3microg/kg, and remifentanil 0.5microg/kg, respectively. After one minute, rocuronium 0.6 mg/kg was injected over 10 seconds. The patient's response after injection was graded using a four-point scale. The patient's heart rate (HR), mean arterial pressure (MAP) were measured at pre-anesthesia (T0), 1 minute after injection of thiopental sodium (T1), test drug (T2), and rocuronium (T3). RESULTS: The incidence of withdrawal responses was 100%, 66.7%, and 20% in groups I, II, and III, respectively. In addition, the severity of withdrawal responses was lowest in group III. CONCLUSIONS: Remifentanil 0.5microg/kg was an appropriate dose to prevent the withdrawal responses on injecting rocuronium.